Conventionally, a pupil modulation technique using an LCOS-SLM (liquid crystal on silicon-spatial light modulator) is known (see PTL 1, for example). A phase modulation type spatial optical modulation element including an LCOS element can arbitrarily change phase distribution of light that is incident on a pupil of an objective lens, thereby forming multiple spots simultaneously on a position of an image so that it is possible to stimulate simultaneously a plurality of stimulation points on a specimen.